On late model vehicles, BMW uses a microfilter to clean the air being passed to the passenger compartment. The unit cleans pollen, dust and other particles from the air to allow better driving comfort. A reduced flow of air from the vents is an indication of a clogged microfilter.
REMOVAL & INSTALLATION
3 Series Models
- Open the glove compartment door and remove the inside trim at the heater side.
- Remove the glove compartment door straps and the hinge mounting nuts. Remove the door.
- Remove the screws holding the cover on the side of the heater unit. Remove the microfilter from under this cover.
- Install the filter, cover and glove compartment door.
- Remove the glove compartment and pull the trim panel out from the rear clip.
- Remove the cover by disconnecting the clip and pulling out. Remove the air duct screws and lift out.
- Disconnect the wires from the control unit. Remove the stage from the filter cover.
- Remove the cover screw and turn the holder. Remove the cover and the filter.
- Install the filter, cover and stage. Connect the control unit.
- Install the air duct and the cover. Install the trim panel and the glove compartment.